A tread typically includes a base layer and a cap layer. The base layer is formed of a crosslinked rubber which is excellent in adhesiveness. The cap layer is formed of a crosslinked rubber which is excellent in abrasion resistance. As a method for forming the base layer and the cap layer, a strip-wind method is known. In the strip-wind method, a first strip that is formed of an uncrosslinked rubber and ribbon-shaped is helically wound to form a winding for the base layer. Over this winding, a second strip that is formed of another uncrosslinked rubber and ribbon-shaped is helically wound, to form a winding for the cap layer. The winding for the cap layer is joined to and integrated with the winding for the base layer due to adhesiveness of the uncrosslinked rubber. The strip-wind method is disclosed in JP2002-160508.